Much of nation to keep on sweating

A warning issued on Tuesday by the National Meteorological Center marked the 19th consecutive day of hot weather alerts, during which some eastern cities have seen record high temperatures.

The center also warned of the increased risk of heatstroke due to humidity. Health risk warnings are based on a five-level scale - in addition to the familiar four-level color codes for heat warnings. Health risks are now at the highest of the five levels in 12 provinces and municipalities in eastern and northwestern China, the center said.

It means residents in places such as Shanghai and the provinces of Zhejiang, Jiangsu, Hubei and Hunan are at risk of heatstroke and should take precautions to keep cool - including the avoidance of extended outdoor activity.